Kinetics of point defects in electron irradiated MgO

Temperature dependence of lattice disorder in Ar-irradiated (100), (110) and (111) MgO single crystals

“…The lack of damage peaks indicates that at 1100°C, most of the lattice damage due to atoms displaced into interstitial positions, is recovered. The linear increase in RBS/C yield may be attributed to the presence of extended defects, which are commonly observed in irradiated MgO [9][10][11][12].…”

“…From the electron irradiation studies it was found that dislocation loop density decreased and loop diameter increased, with increasing irradiation temperature (T irr ). Also, a pronounced change in the slope of the dislocation density versus T irr was observed at $600°C [10,11]. The authors proposed that the observed slow decrease of dislocation loop density below 600°C may be attributable to a dislocation loop nucleation mechanism controlled by migration of only Mg and O interstitial atoms.…”

“…On the other hand, the sharp reduction in the dislocation loop density observed above 600°C is likely to be related to enhanced mobility of both interstitial and vacancies. For electron irradiations at T irr = 860°C, void type defects were observed along with the dislocation loops [11]. No voids were observed in the neutron and ion irradiation experiments [9,12].…”

“…High temperature irradiation studies to date report specifically on microstructural evolution, evaluated using transmission electron microscopy (TEM). These TEM studies include investigations of single crystal (1 0 0) MgO samples irradiated with: (i) fast neutrons at 200 and 650°C [9]; (ii) high-energy electrons in the temperature range, 25-1000°C [10,11]; and (iii) ions at temperatures between 500 and 800°C [12]. These studies revealed that dislocation loops of interstitial type formed, independent of the irradiation particle type.…”

Effect of helium on dislocation loop formation and radiation swelling in SiC

“…This is the typical situation for the evolution of defect microstructure in ceramic materials after the onset of irradiation [11,12]. In this case the point defect sinks are only the dislocation network and the dislocation loops.…”